Millipedes Invading Homes and Garages

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garden millipede

Common garden millipedes seek higher ground during wet weather. Image by Gary Alpert, Harvard University. Bugwood.org

If your garage, home, shed, beehive, or any other dry structure has been invaded by millipedes in the past few weeks blame it on the wet weather. These many legged arthropods are simply seeking higher ground to avoid drowning. The good news is garden millipedes only feed on decaying organic matter; they do not bite, sting, or transmit diseases, nor do they infest plants, food, clothing or wood. Like many home invading insects, they usually die within a few days of entering an air conditioned building because the air is too dry for them to survive. If you have lots of millipedes entering your home the best is advice is to vacuum daily and hope for drier weather.

The following information about millipedes comes from Dr. Mike Waldvogel, NCSU Entomology Extension Specialist:

“Millipedes are common to occasional pests that sometimes invade structures. Millipedes vary greatly in size and color. The most common species that invades buildings is the garden millipede, which is brownish-black in color and about one inch long. Although millipedes are often called “thousand-leggers” they actually have far fewer legs, but each body segment has two pairs of very short legs. Millipedes are often confused with centipedes; however, centipedes only have one pair of legs per body segment.

Millipede invasions are triggered by very hot and dry conditions or when it’s too wet and water-saturated soils force them to the surface and higher ground. Millipedes may also migrate in the fall, presumably in search of overwintering sites. All of these activities result in millipedes invading crawl spaces, basements and other areas of buildings.

Millipedes are most likely to invade areas where moisture tends to accumulate, usually crawl spaces, basements, and garages. Buildings with slab construction may face more problems in that millipedes have a somewhat shorter trek up the exterior surface. However, millipedes are skilled climbers and often make their way up to a second floor or even to the roof of a house.

Millipedes do not survive long indoors, but typically long enough to raise the frustration level of the homeowner. They can be particularly unsettling when they invade in large numbers. When controlling millipedes, emphasis should be placed first on reducing excess moisture and hiding places, especially around the foundation. Heavy accumulations of leaves, grass clippings, and mulch around the foundation should be removed. This does not mean that mulch cannot be used around the foundation; simply keep it 6 to 12 feet away from the wall. Wooden boards, stones, boxes, and similar items should be stored away from the foundation. Prevent water from accumulating around the foundation, in crawl spaces, or in basements. Make sure gutters and down spouts are free of debris and use either splash-guards or perforated pipe to reduce puddles.

To help prevent millipede invasion, cracks and other openings in the outside foundation walls and around doors and windows can be sealed with caulk. Door sweeps on exterior entry doors can be installed and maintained in good condition. Application of insecticides along baseboards and other interior living areas of the home do not really stop millipede invasions. Once indoors, millipedes soon die from a lack of moisture. Remove them with a vacuum cleaner or broom.”

Learn More!

NC State Extension millipede factsheet:  https://www.ces.ncsu.edu/depts/ent/notes/Urban/millipedes.htm

Use Extension Search to find research based information from Cooperative Extension systems across the U.S.

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